This invention relates to mobile vehicle engine cooling systems and the process for installation of such systems. Such vehicles appropriate for such installation include light, medium, and heavy-duty trucks.
Engine cooling systems contain a radiator or heat exchanger in which engine coolant is circulated for cooling. The radiator is in line for the passage of ambient air from a combination of ram movement from the vehicle and an engine fan. School buses and medium and heavy-duty trucks have chassis that have two generally parallel frame rails. These frame rails are jointed by a series of cross members. The frame rails act as the mounting point for a number of the chassis components as well as the cab of the vehicle. The prior art engine cooling system radiator mounting systems allowed fore aft adjustment to the cooling module. When the mounting angle of the radiator varies, it causes tolerance stack up problems with other components in the vicinity of the cooling package. This fore aft adjustment also allows variability in the mounting isolator compression. Uneven or preloaded compression of mounting isolators directly affects isolation of cooling module movement and the life expectancy of the actual isolator. The methods of mounting the cooling module onto the isolators and the mounting brackets are also a contributor to the uneven or preloaded mounting isolators.
One prior art method of mounting cooling modules was to mount the module without preloading the isolators by inserting the isolator into a hole in the mounting bracket and carefully lowering the module with a mounting bolt down into the isolator. Then the module would need to be centered and lowered onto the mounting bracket without preloading the isolator. Then the fore aft angle of the module was set by tightening down on the bolts along the centerline of the stay rod until the isolators on the stay rods compressed and bottomed out against a stop flange on the stay rod.
What is needed and does not exist in the prior art is a method of installing a cooling system module that allows preload of the isolators for the radiator prior to installation to the vehicle and a vehicle manufactured in such a manner.
An object of the invention is to provide a method of installing a cooling system module that allows preload of the isolators for the radiator prior to installation to the vehicle and a vehicle manufactured in such a manner
The method of this invention of mounting a cooling package to a vehicle and the module are described as follows. The chassis cross member for providing vertical support to the cooling package is sub-assembled to the cooling module separate from the vehicle where the two mounting surfaces can be held parallel to one another eliminating the possibility of unevenly preloading the isolator. Then this pre-assembled isolated system can be mounted on the truck chassis without changing the relationship of the compressed isolator when the module is bolted down during truck assembly. This system eliminates the fore aft adjustment variability. The elimination of the fore aft adjustment also allows for more control over the static location and isolator compression of the cooling module in the truck. The stay rods used eliminate variation in the rod isolator compression during mounting. The stay rod also allows for controlled multi-axial movement with a mounting centerline perpendicular to the input loads. The prior art isolators only allow input loads along the rod centerline in a fore aft direction.
This mounting system allows the cooling module to be completely plumbed to the engine before the main assembly line engine module drop. This also supports a manufacturing process that can mount isolators in a controlled manner prior to the engine module drop. Frame mounted castings provide a positive locating feature for the cooling modules height, fore/aft and side to side locations as well as setting the angle for proper stay rod alignment. Additional effects, features and advantages will be apparent in the written description that follows.